Presently available isokinetic equipment operates on the principle of so-called "accommodating resistance"; that is, the effort expended by the user in moving an operating lever or the like will be matched by the equipment throughout the full range of muscular contraction of the user. Consequently, even though changes in the locations of pivot points, the lengths of lever arms, etc. will vary in the user's arms and legs as he moves the operating lever through an exercising stroke so as to enable the user to obtain better leverage against the resistive force supplied by the equipment, nonetheless the isokinetic equipment "accommodates" the changing conditions and at all times matches the effort being expended by the user, thus assuring that the user's muscles are taxed throughout the full range of their contracting movement.
These prior devices have by and large utilized a pair of relatively rotatable members whose frictional interengagement during such rotation creates the resistance needed to match the user's input efforts, and as long as the user moves the operating lever or handle at the same speed throughout the exercising stroke, the resistance furnished by the machine would remain the same.